Deepwater hydraulic power unit



April 7, 1970 F. A. KRIEDT 3,504,648

DEEPWATER HYDRAULIC POWER UNIT Filed April 29, 1968 4 Sheets-Sheet 1 INVENTOR FREDERICK A. KR/EDT I BY 5) g a i ATTORNEYS F. A. KRIEDT DEEPWATER HYDRAULIC POWER UNIT April 7, 1910 4 Sheets-Sheet 4 Filed April 29, 1968 mwm INVENTOR FREDERICK 4. 109/507 ATTORNEYS United States Patent 3,504,648 DEEPWATER HYDRAULIC POWER UNIT Frederick A. Kriedt, 1819 M St. NW., Washington, D.C. 20036 Filed Apr. 29, 1968, Ser. No. 725,027 Int. Cl. B63g 8/00; F01b 29/00; F03b 13/10 U.S. Cl. 114-16 7 Claims ABSTRACT OF THE DISCLOSURE The present invention is a power unit for a deep submersible vessel deriving its motive power from seawater at a great pressure, throttled through a positive displacement fluid motor into an evacuated sphere.

The invention described herein may be manufactured and used by or for the Government of the United States of America for government purposes without the payment of any royalties thereon or therefor.

BACKGROUND OF THE INVENTION The present invention relates to prime movers and more particularly pertains to such devices deriving their motive power from the pressure differential between an evacuated sphere and seawater at great depths.

With the increased interest in ocean technology, many vehicles have been built to record scientific data far below the ocean surface. The need has long exists for efficient prime movers which are not dependent upon combustible fuels for their operation. Such devices would have wide application in a variety of uses. One well known form of prime mover is the water wheel. For eflicient operation, the water wheel requires a large head of water, and this frequently presents a serious problem.

Prior art devices have utilized power from that inherent property in a body, buoyancy that permits it to float to the surface of a liquid medium. The upward force exerted on an immersed body by the supporting medium, was converted to a rotary motion by passing successive floats through a fluidfree air look into the fluid medium wherein the buoyant forces set up moments about a central axis. Other devices utilized a power mechanism operable by pressure of the water in which a boat was partially submerged with additional means to impart additional pressure while in circulation to cooperate with the water under normal pressure.

SUMMARY The general purpose of this invention is to provide a propulsive unit on a deep diving search or oceanographic vehicle that has all of the advantages of similarly employed prime movers, and has none of the disadvantages. To attain this, the present invention utilizes the large pressure differential at deep depths. In order to better understand the principles involved in the present invention, an analogy to a known physical phenomenon may be helpful.

One of the problems which has arisen while developing the deep sea diving vehicles is damage caused by implosion. Due to the scientific nature of these vehicles, it is very often necessary to put instruments outside the pressure hull to record scientific data. The. instruments must be protected from the extreme pressures by constructing a housing. If this protective housing should fail at some given depth, energy is released, proportional to the pressure times the change in volume. The mechanism of energy release has been named implosion. If the implosion energy is absorbed by a structure in the vicinity of the implosion, damage may result thereby causing a catastrophic situation.

3,504,648 Patented Apr. 7, 1970 The present invention utilizes the available energy in seawater at great pressures by lowering a sphere capable of withstanding extremepressures to a working depth. Seawater at a great pressure is throttled through a positive displacement fluid motor into the sphere containing a vacuum. The fluid motor may be coupled directly to a drive mechanism or to a generator for supplying electrical power.

An object of the invention is to provide a durable and economical power unit to produce power for operating machinery.

Another object of the invention is to provide a prime mover for submersible's.

A further object of the invention is to provide a power unit which converts seawater pressure to usable power.

Still another object is to utilize fluid flow from a high pressure area to a low pressure area to power a fluid motor.

With these and other objects in view, as will hereinafter more fully appear, and which will be more particularly pointed out in the appended claims, reference is now made to the following description taken in connection with the accompanying drawings in which:

FIG. 1 schematically illustrates the operating principles of the present invention.

FIG. 2 is a graphical representation of power available at 20,000 ft.

FIGS. 3 and 7 are graphical representations of power available as a function of depth and sphere radius.

FIG. 4 is a graphical representation of variable ballast as a function of sphere radius.

FIGv 5 is a plan view in section of one embodiment of the present invention.

FIG. 6 is a side view in section of an alternative embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 1, the present invention is shown in schematic form. For purposes of illustration, an evacuated sphere 11 is provided with a fluid conduit 12, which in turn is connected through a fluid motor 13, to a throttle valve 14. The throttle valve 14 is connected on one side to the input end of fluid motor 13 through a conduit 15 and on the other side through conduit 16 to a seawater inlet 17.

The evacuated sphere 11 may preferably be fabricated from glass or other spherical structural material capable of withstanding great pressures. The fluid motor 13 may preferably be a positive-displacement pump or fluid motor, e.g., a slow speed piston type motor has the greatest efficiencies at high pressures. A particular model which may be used is a hydraulic motor capable of handling brine having a .2 cu. in. displacement, 10 HP. 3,000 r.p.m. with an efiiciency of 87% or greater.

FIG. 2 is a graphical representation of the actual available power in a system utilizing the principles of this invention. An efliciency of was assumed and actual values of power were calculated using data for hydraulic machinery. These values were plotted against sphere diameter. For example, for a sphere with a 4-foot radius, a value of H.P. hours could be obtained at 20,000 feet. As shown in FIG. 3, the power would increase linearly with an increase in depth.

Utilizing an evacuated chamber such as sphere 11 would necessitate the use of ballast to compensate for the intake of seawater. As shown in FIG. 4, utilizing a sphere with a raduis of 4 feet, 8 tons of ballast is required.

Referring to FIG. 5 there is shown a preferred embodiment utilizing the principles of this invention. Numeral 18 designates a vessel hull or boat of any suitable construction. Seawater inlets 17 are the main inlet ports and communicate directly with the water in which the vessel is submerged through suitably constructed openings 19 in the vessel 18. The fluid motor 13 is provided with inlet ports 21 and outlet port 22 to direct propulsive fluid flow through and out of the fluid motor 13. Connected to outlet port 22 of fluid motor 13 is fluid conduit 12 communicating through throttle valve 14 with sphere 11. Communicating with throttle valve 14 is control line 14c of any suitable well known construction. Control line 14c may take the form of a mechanical linkage for turning a needle valve or electrical or hydraulic means for metering liquid flow.

Also mounted on the vessel hull 18 are maneuvering units 23L and 24R may be fixed in position, thereby controlling the change of direction of the vessel by alternate energization, e.g. energizing 23L will turn the vessel to the right and vice versa. The maneuvering units 23L and 24R may also be rotatable on vessel hull 18 thereby providing turning and/or lifting moments to control the attitude and direction of the vessel 18. Fluid flows through maneuvering unit 23L, through conduit 25, in a volume as controlled by throttle valve 26 into sphere 11. Similarly, fluid flows through maneuvering unit 24R, through conduit 27, in a volume as controlled by throttle valve 28 into sphere 11. Control lines 26C and 28C provide metering flow control for throttle valves 26 and 28 respectively.

A mercury or other well known suitable trim system 29 is a standard item on deep submersibles and does not form a part of this invention although some form of trim system is essential to efficient operation of the apparatus in accordance with this invention.

Seawater ballast tanks 30 are filled to allow the submersible to sink to its design depth. The tanks 30 are not shown in detail as they are standard equipment on deep submersibles.

THEORY OF OPERATION At the surface, prior to diving, the sphere 11 is evacuated utilizing a seawater pumpout connection and pumps aboard the support vessel. The lead. shot basket 33, a variable ballast system, is filled with lead shot. The seawater ballast tanks are also filled, thereby permitting the vessel to submerge. As the vessel reaches the desired depth, the pilot within the vessel controls the depth of the vessel by controling the variable ballast via control line 33C and the flow of fluid through the maneuvering units 23L and 24R and/or the propulsive unit fluid motor 13.

The lead shot and the throttling valves are programmed or may be controlled to keep the buoyancy of the vessel constant at all times.

By opening the throttling valves on any of the propulsive units, seawater at a high pressure is permitted to flow through the fluid motors 13, 23L or 24R as desired, and into the evacuated sphere 11 thereby providing motive power. Simultaneously the lead shot variable ballast is ejected from the lead shot basket 33 thereby keeping the buoyancy constant. As soon the sphere 11 is completely filled with water, accent weights (not shown) are dropped, thereby permitting the vessel to return to the surface. At the surface, the sphere 11 is evacuated and the lead shot basket 33 is refilled, thus permitting another submergence cycle.

FIG. 6 shows an alternative power unit utilizing apparatus in accordance with the invention. The power unit basically comprises sphere 11', fluid motor 13' and throttle valve 14' performing in a manner similar to the hydraulic propulsion unit described in connection with FIG. 5. Since the power unit will be used to provide electrical power to test equipment attached to the power unit, a D.C. motor generator 34 may be used instead of a propulsive unit. The fluid motor 13' may be mechanically coupled by power shaft 35 to a DC. motor generator 34 which preferably is encased in an oil filled container. Generator leads 36 lead to a power input terminal (not shown) on the test equipment.

The entire power unit is encased in a buoyant material 37 having suflicient strength to withstand crushing at great depths e.g. gasoline, syntactic foam. The positive buoyancy of buoyant material 37 is initially overcome by ballast tanks 29 and concrete ballast 38. Ballast 38 may be attached to the power unit by a release mechanism 39 of any suitable well known design ca pable of being released or detached by transponders. For example, the release may be triggered by a timing signal from the power unit or an external signal received from the support vessel.

An intake valve 41 is provided in intake line 42 to control the starting and stopping of the power unit whereas throttle valve 14' controls the rate of flow of the fluid under pressure. Discharge valve 43 is provided in discharge line 44 and is used in evacuating sphere 11. Suitable electrical or mechanical valve controls 45 may be provided to control their associated valves.

THEORY OF OPERATION Initially the ballast tanks 29' are empty and the concrete ballast 38 is attached to the unit. The sphere 11' is evacuated and is essentially at a vacuum. The necessary test equipment is attached to the top deck 46 of the power unit and the generator leads 36 are attached. The throttle valve 14' is set in relation to the power requirements of the attached equipment.

The ballast tanks 29' are flooded using the ballast valves 47 and 48 thereby creating a negative buoyant eflect. The entire unit then begins to submerge, usually to the ocean bottom. Intake valve 41 may then be actuated by a transponder by an initiating signal from the support vessel. Seawater at ambient conditions (very high pressure) is then throttled through the valve 14' into fluid motor 13' and into the evacuated sphere 11'. The fluid motor 13", through power shaft 35, drives a DC. motor generator 34 thereby providing electrical power to generator leads 36 to the equipment package.

When the sphere 11' is filled with water, the concrete ballast 38 is released by release mechanism 39 actuated by transponders. When the concrete ballast 38 is released, the net buoyancy of the power unit is positive, thus it rises to the surface for recovery.

If it should be desirable to use a non-corrosive fluid, e.g. oil, as a power fluid, containers or bags of non-corrosive fluid may be added to the deck 46 and connected at the seawater intake 40. The seawater pressure at the great depth will then be used to force the non-corrosive fluid through seawater intake 40, through throttle valve 14, fluid motor 13' and into sphere 11' until the sphere 11' is full.

The power unit, excluding the sphere 11, is shown in FIG. 6 as a removable unit 49 held in position by securing means 51. This particular feature provides rapid replacement of components and ready access for maintenance and calibration.

Thus a propulsive unit and a power unit for use on a deep diving search or oceanographic vessel has been described. By utilizing the power unit of this invention, losses due to electromechanical conversion may be eliminated or greatly reduced. Furthermore, the invention provides a power unit which converts seawater pressure to usable power for operating machinery in a more eflicient manner.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. In a power unit for a maneuverable deep sea submersible vessel deriving power from fluid at a great pressure, the combination comprising:

a high volume, hollow, evacuated sphere capable of withstanding extreme external pressures;

conversion means communicating with said sphere and said fluid for converting the pressure of said fluid into useful power; and

means for controlling the rate of flow of said fluid through said conversion means to said sphere,

whereby fluid is metered through said conversion means at a desired rate dependent upon power requirements.

2. A power unit of the type defined in claim 1 wherein said sphere is made of glass.

3. A power unit of the type defined in claim 1 wherein said conversion means comprises:

a fluid motor; and

maneuvering means communicating with said fluid motor for controlling the attitude and direction of the submersible vessel.

4. A power unit of the type defined in claim 1 wherein said conversion means comprises:

a fluid motor; and

an electrical generator coupled to said fluid motor for generating electrical power.

5. A power unit of the type defined in claim 1 wherein said means for controlling the rate of flow of said fluid comprises:

a fluid valve.

6. In a maneuvering unit for a deep submersible vessel deriving power from fluid at a great pressure, the combination comprising:

a sphere capable of withstanding extreme pressures and having a diameter dependent upon the desired power capacity;

a positive displacement fluid motor having a fluid output communicating with said sphere, said motor having a fluid input and having a power output;

maneuvering means communicating with said power output for controlling the attitude and direction of said deep submersible vessel; and

valve means controlling fiow in a fluid conduit between said fluid under pressure and said positive displacement fluid motor,

whereby said fluid is metered at a desired rate dependent upon power requirements and converted into useful motive power.

7. In a maneuverable deep diving submersible vehicle having a power operated means for electrically controlling the vehicle maneuvering means, and a variable ballast system for regulating the buoyancy of the vehicle, a power unit comprising:

a sphere capable of withstanding extreme pressures and having a diameter dependent upon the desired power capacity;

a positive displacement fluid motor having a fluid output communicating with said sphere, said motor having a fluid input and having a power output;

an electrical generator coupled to said fluid motor for generating electrical power;

throttle valve means controlling flow in a fluid conduit between said fluid under pressure and said positive displacement fluid motor; and

transponder actuated valve means in said fluid conduit for starting and stopping said fluid input in response to an external signal,

whereby said fluid is metered at a desired rate dependent upon power requirements and converted into useful electrical power.

References Cited UNITED STATES PATENTS 700,769 5/1902 Hazard 114-16 3,118,417 1/1964 Stanwick 114-206 3,163,985 1/1965 Bouyoucos 6051 3,205,969 9/1965 Clark 6051 XR 3,371,643 3/1968 Dunham 114--206 EDGAR W. GEOGHEGAN, Primary Examiner US. Cl. X.R. 60-51, 60 

